<!DOCTYPE html>
<html>

<head>
  <title></title>
  <script type="text/javascript">
  class Point {
    constructor(x = 10, y = 100) {
      this.x = x;
      this.y = y;
    }

    add(x = 3, y = 2) {
      this.x += x;
      this.y += y;
    }

    toString() {
      return `(${this.x}, ${this.y})`;
    }
  }

  console.log(typeof Point);

  var point = new Point(11);
  console.log(point.toString());
  point.add();
  console.log(point.toString());
  </script>
</head>

<body>
</body>

</html>